Bernard J. Costello

In vivo study of magnesium plate and screw degradation and bone fracture healing.

Each year, millions of Americans suffer bone fractures, often requiring internal fixation. Current devices, like plates and screws, are made with permanent metals or resorbable polymers. Permanent metals provide strength and biocompatibility, but cause long-term complications and may require removal. Resorbable polymers reduce long-term complications, but are unsuitable for many load-bearing applications. To mitigate complications, degradable magnesium (Mg) alloys are being developed for craniofacial and orthopedic applications. Their combination of strength and degradation make them ideal for bone fixation. Previously, we conducted a pilot study comparing Mg and titanium devices with a rabbit ulna fracture model. We observed Mg device degradation, with uninhibited healing. Interestingly, we observed bone formation around degrading Mg, but not titanium, devices. These results highlighted the potential for these fixation devices. To better assess their efficacy, we conducted a more thorough study assessing 99.9% Mg devices in a similar rabbit ulna fracture model. Device degradation, fracture healing, and bone formation were evaluated using microcomputed tomography, histology and biomechanical tests. We observed device degradation throughout, and calculated a corrosion rate of 0.40±0.04mm/year after 8 weeks. In addition, we observed fracture healing by 8 weeks, and maturation after 16 weeks. In accordance with our pilot study, we observed bone formation surrounding Mg devices, with complete overgrowth by 16 weeks. Bend tests revealed no difference in flexural load of healed ulnae with Mg devices compared to intact ulnae. These data suggest that Mg devices provide stabilization to facilitate healing, while degrading and stimulating new bone formation.

Cleft Lip and Palate Surgery: An Update of Clinical Outcomes for Primary Repair

The comprehensive management of cleft lip and palate has received significant attention in the surgical literature over the last half century. It is the most common congenital facial malformation and has a significant developmental, physical, and psychological impact on those with the deformity and their families. In the United States, current estimates place the prevalence of cleft lip and palate or isolated cleft lip at approximately 1 in 600. There is significant phenotypic variation in the specific presentation of facial clefts. Understanding outcome data is important when making clinical decisions for patients with clefts. This article provides an update on current primary cleft lip and palate outcome data.

Noggin inhibits postoperative resynostosis in craniosynostotic rabbits

Inhibition of bone formation after surgery to correct craniosynostosis would alleviate the need for secondary surgeries and decrease morbidity and mortality. This study used a single dose of Noggin protein to prevent resynostosis and improve postoperative outcomes in a rabbit model of craniosynostosis.

Fracture Healing Using Degradable Magnesium Fixation Plates and Screws

PURPOSE Internal bone fixation devices made with permanent metals are associated with numerous long-term complications and may require removal. We hypothesized that fixation devices made with degradable magnesium alloys could provide an ideal combination of strength and degradation, facilitating fracture fixation and healing while eliminating the need for implant removal surgery. MATERIALS AND METHODS Fixation plates and screws were machined from 99.9% pure magnesium and compared with titanium devices in a rabbit ulnar fracture model. Magnesium device degradation and the effect on fracture healing and bone formation were assessed after 4 weeks. Fracture healing with magnesium device fixation was compared with that of titanium devices using qualitative histologic analysis and quantitative histomorphometry. RESULTS Micro-computed tomography showed device degradation after 4 weeks in vivo. In addition, 2-dimensional micro-computed tomography slices and histologic staining showed that magnesium degradation did not inhibit fracture healing or bone formation. Histomorphology showed no difference in bone-bridging fractures fixed with magnesium and titanium devices. Interestingly, abundant new bone was formed around magnesium devices, suggesting a connection between magnesium degradation and bone formation. CONCLUSION Our results show potential for magnesium fixation devices in a loaded fracture environment. Furthermore, these results suggest that magnesium fixation devices may enhance fracture healing by encouraging localized new bone formation.

Mortised genioplasty in the treatment of obstructive sleep apnea: an historical perspective and modification of design.

We describe a modified technique for mortised genioglossus advancement for treating obstructive sleep apnea and review the history of osteotomies in this region. This new osteotomy technique allows for greater soft tissue advancement of the hypopharyngeal region. Anatomical data from a previous study were used to evaluate the dimensions of the anterior mandible and design an osteotomy that overcomes shortcomings of previous designs. These anatomic measurements enabled us to estimate the size and formulate a design utilized in the anterior mandible for the treatment of obstructive sleep apnea. We believe this design offers the greatest amount of muscular advancement by including genioglossus, geniohyoid, digastric, and mylohyoid. This advancement results in increasing the posterior airway space by volumetric expansion. Custom-designed fixation was utilized to increase stability laterally and decrease the risk of mandibular fracture. The design should be a significant aid in reconstruction of the hypopharyngeal airway in patients with obstructive sleep apnea.

Revisiting the recurrence risk of nonsyndromic cleft lip with or without cleft palate

Sub‐epithelial defects (i.e., discontinuities) of the superior orbicularis oris (OO) muscle appear to be a part of the phenotypic spectrum of cleft lip with or without cleft palate (CL ± P). Analysis of the OO phenotype as a clinical tool is hypothesized to improve familial recurrence risk estimates of CL ± P. Study subjects (n = 3,912) were drawn from 835 families. Occurrences of CL ± P were compared in families with and without members with an OO defect. Empiric recurrence risks were calculated for CL ± P and OO defects among first‐degree relatives (FDRs). Risks were compared to published data and/or to other outcomes of this study using chi‐square or Fishers exact tests. In our cohort, the occurrence of CL ± P was significantly increased in families with OO defects versus those without (P < 0.01, OR = 1.74). The total FDR recurrence of isolated OO defects in this cohort is 16.4%; the sibling recurrence is 17.2%. The chance for one or more FDRs of a CL ± P proband to have an OO defect is 11.4%; or 14.7% for a sibling. Conversely, the chance for any FDR of an individual with an OO defect to have CL ± P is 7.3%; or for a sibling, 3.3%; similar to published recurrence risk estimates of nonsyndromic (NS) CL ± P. This study supports sub‐epithelial OO muscle defects as being part of the CL ± P spectrum and suggests a modification to recurrence risk estimates of CL ± P by utilizing OO defect information.

Regeneration of periosteum by human bone marrow stromal cell sheets.

PURPOSE The presence of a functional periosteum accelerates healing in bone defects by providing a source of progenitor cells that aid in repair. We hypothesized that bone marrow stromal cell (BMSC) sheets could be used to engineer functional periosteal tissues. MATERIALS AND METHODS BMSCs were cultured to hyperconfluence and produced sufficient extracellular matrix to form robust tissue sheets. The sheets were wrapped around calcium phosphate pellets and implanted subcutaneously in mice for 8 weeks. Histologic comparisons were made between calcium phosphate samples with and without BMSC sheet wraps. Bone and periosteum formation were analyzed through tissue morphology and tissue-specific protein expression. RESULTS Calcium phosphate pellets wrapped in BMSC sheets regenerated a bone-like tissue, but pellets lacking the cell sheet wrap did not. The bone-like tissue seen on the calcium phosphate scaffolds wrapped with the BMSC sheets was enclosed within a periosteum-like tissue characterized morphologically and through expression of periostin. CONCLUSIONS These data indicate that cell sheet technology has potential for regenerating a functional periosteum-like tissue that could aid in future orthopedic therapy.

Fetal Diagnosis and Treatment of Craniomaxillofacial Anomalies

So many advances in health care are built on the evolution of technology. In the case of fetal medicine, technology has availed an entirely new patient. Advances in prenatal imaging allow us to see and diagnose disease not previously appreciated. Armed with this information, clinicians can better plan for the delivery of the neonate such that any identified anomalies are optimally managed, and the impact on the neonates health minimized. The oral and maxillofacial surgeon can be a key member in this team by offering expertise in the management of craniomaxillofacial anomalies including congenital tumors, facial clefts, craniosynostosis, micrognathia, and other congenital abnormalities. The techniques for perinatal care of the patient with craniofacial abnormalities continue to evolve as the technology improves. The review of the cases presented at the University of Pittsburgh Fetal Diagnosis and Treatment Team during the past 6 years has shown many opportunities for craniomaxillofacial prenatal evaluation. We describe our recent experience and some of the more common abnormalities with their management considerations that may be encountered by the oral and maxillofacial surgeon on the fetal diagnosis and treatment team.

Retrieval of a Displaced Third Molar Using Navigation and Active Image Guidance

An 18-year-old healthy female patient had a consultation with another surgeon for removal of pathologically impacted third molars, and surgical removal of the teeth was recommended (Fig 1). The complete bony impactions were approached in typical fashion using a small incision along the lateral aspect of the alveolar crest in the area of the impacted tooth. A subperiosteal dissection was appropriately completed, but during elevation the right maxillary third molar was displaced beneath the flap. An immediate exploration was performed to locate the tooth but was subsequently terminated without success. Postoperatively, the patient displayed diplopia on upward gaze, warranting evaluation by an ophthalmologist. Visual acuity and all other aspects of her examination were normal with the notable exception of diplopia on extreme upward gaze. A CT scan was obtained to localize the now “foreign-body,” and the patient was referred to the senior author for treatment (Fig 2). A minor orbital disruption was noted on the scan, with disruption of the tissues surrounding the inferior rectus. After 6 weeks of healing the patient was scheduled for surgical removal of the displaced tooth and, now, foreign body. At 6 weeks, the diplopia had almost completely resolved and was only present during extreme upward gaze. A computed tomography scan was obtained as per the protocol for use with the Stryker System II Navigation image guidance apparatus (Stryker, Kalamazoo, MI). The patient was brought to the operating theater and placed under general anesthesia with a nasal endotracheal tube. The Stryker System II uses a light emitting diode (LED) mask to register the CT data with the patient in the operating theater and correlates the data with the hand-held probe/ suction device (Fig 3). An accuracy of 0.5 mm was anticipated after calibrating the system. Multiple views allowed localization of the tooth within minutes (Fig 4). A small vestibular incision was made beneath the zygomatic buttress, and a suction/probe was used to determine the exact location of the medial and lateral aspects of the occlusal surface of the tooth. After precise localization the tooth was bluntly dissected free and removed (Fig 5). Blood loss was minimal, and the incision was closed with a running 3-0 chromic suture. The entire procedure was completed within minutes, and the patient was discharged several hours later. Discussion Complications from third molar removal are, thankfully, rare. The most common complications occur with regular frequency. These include infection (0.8% to 4.2%), 7-13 alveolar osteitis (0.3% to 26%), 7-15 inferior alveolar nerve injury (0.4% to 8.4%), 8,18,19 lingual nerve injury (0% to 23%, 10,18,20 with approximately 0.5% being permanent 21-23 ), and clinically significant hemorrhage (0.1% to 0.7%). 7,10,24 Rare complications of third molar removal include mandible fracture (0.0033% to 0.0049%), 16,17 osteomyelitis, and displacement of teeth during removal, for which the incidences are unknown. It is likely that displacement of teeth during removal of third molars is under-reported, as most surgeons retrieve their own displacements without reporting the complications.

Velopharyngeal insufficiency in patients with cleft palate.

Bernard J. Costello, DMD, MD*, Ramon L. Ruiz, DMD, MD, Timothy A. Turvey, DDS Departments of Oral and Maxillofacial Surgery, Pediatric Dentistry, and Pediatric Surgery, University of Pittsburgh Medical Center, Magee-Women’s Hospital, and Children’s Hospital of Pittsburgh, Pittsburgh, PA 15213, USA University of Pittsburgh Cleft Palate-Craniofacial Center, Pittsburgh, PA 15213, USA University of Pittsburgh School of Dental Medicine, 3471 Fifth Avenue, Suite 1112, Pittsburgh, PA 15213, USA Department of Oral and Maxillofacial Surgery, University of North Carolina Craniofacial Center, University of North Carolina at Chapel Hill, USA Pediatric Oral and Maxillofacial Surgery, North Carolina Children’s Hospital, Brauer Hall, CB# 7450, Chapel Hill, NC 27599-7450, USA